This invention relates generally to an antenna assembly and, more particularly, to a collapsible, steerable antenna assembly configured for rapid deployment.
Traditionally, to receive an adequate signal from a communication satellite, an antenna had to be securely fitted to a rigid mount which was adjustable in both azimuth and elevation. Later, antennas began being mounted on moving vehicles. These antenna systems were required to be adjustable in elevation sufficiently to suit the latitude of the vehicle. In addition, portable antenna systems also began to develop. These portable systems were also required to be adjustable in elevation sufficient to suit the latitude of the ground at which they were located.
The use of portable antenna systems and other electronic equipment in the field today often requires the positioning of an antenna of substantial size, in order to prevent terrestrial interference and interference from other satellites with signal beings radiated or received by the antenna. In addition, the antenna and its support should be sufficiently compact in the stowed position, so as to not interfere with mobility of the antenna in the field.
Portable antenna systems of the general type mentioned above have been built in the past, but suffer from several disadvantages. These include excessive assembly time, a large number of separate pieces, complex assembly procedures which lead to a loss of parts and unreliability, difficulty of assembly, and the requirement of multiple operators to assemble and disassemble the system.
In addition, these systems have been designed with the primary goal of breaking the unit down into multiple light-weight shipping containers that meet the maximum standards for lower lobe airline shipping. This increases the complexity and lengthens the assembly time of the antenna.
Further, past systems have proved inadequate in their ability to minimize distortion in the antenna dish of the system, due to either assembly technique or parametric distortion under the weight of the dish and other system components.
It is desirable for antenna system components to be as adjustable as possible for positioning and alignment efficiency. There is a continuing need for an antenna system that is highly accurate, yet has high modularity and portability, while remaining simple to assembly.
Accordingly, those skilled in the art have long recognized the need for a collapsible, steerable antenna assembly configured for rapid deployment. The present invention clearly fulfills these and other needs.
Briefly, and in general terms, the present invention resolves the above and other problems by providing a horn mount assembly for adjustably positioning a horn assembly with respect to an antenna dish in an antenna system. The horn mount assembly includes a feed strut attachment plate, wave guide mount circular clamp, a horn circular clamp, a flexible wave guide mount, a Z-axis jack screw, and a Y-Z tilt jack screw. The horn mount assembly connects the horn assembly to the main feed leg through the feed strut attachment plate. The horn assembly, the orthomode transducer, and the flexible wave guide mount connect to the horn mount assembly through the wave guide mount circular clamp and the horn circular clamp. The flexible wave guide mount is located at the distal end of the horn mount assembly and provides a connection bracket for the flexible wave guide. The horn circular clamp is located at the proximal end of the horn mount assembly and provides a connection bracket for the horn assembly. The orthomode transducer provides a connection bracket for the flexible wave guide mount and a mount for attaching a rejection filter and satellite receivers/downconverter to the horn assembly.
The Z-axis jack screw facilitates translation of the horn mount assembly and connected horn assembly along the horn transmission beam axis in order to modify the focal length with respect to the centerpoint of illumination of the antenna dish. As used herein, the centerpoint of illumination of the antenna dish is defined as the intersection of the horn transmission beam from the horn assembly and the dish. The axis from the horn assembly to the centerpoint of illumination of the antenna dish is defined as the horn transmission beam axis. The axis along which the reflected beam traverses from the centerpoint of illumination out to an infinite distance from the antenna dish is defined as the transmission beam axis. The Y-Z tilt jack screw facilitates rotation of the horn mount assembly and connected horn assembly. The torque plate is used to apply torque to the wave guide mount that is operatively associated with the horn assembly. The first end of the flex drive torque cable connects to the manual drive and the second end of the torque cable connects to the adjustment knob. Manipulating the adjustment knob facilitates manual polarization adjustment of the horn assembly from a remote location within the length of the flex drive torque cable.
In a preferred embodiment of the present invention, the manual drive is a manual worm drive. Preferably, the torque cable is selectively attachable to the manual drive through a cable disconnect. Further, the cable disconnect provides for quick disengagement of the torque cable from the manual drive without the use of tools. Advantageously, the drive assembly facilitates remote manual polarity adjustment of the horn assembly while the antenna system is actively transmitting a signal for increased signal alignment efficiency. This allows for ease of polarity adjustment in situations where the back frame and antenna assembly are to be setup without the three axis tombstone controller steering head, as in fixed antenna installations.
In a preferred aspect of the present invention, the manual drive is selectively securable to a main feed leg of the antenna system, thereby facilitating polarization adjustment of the horn assembly with respect to the position of the main feed leg. Preferably, the positioning of the manual worm drive is such that the transmission signals of the antenna system are free from interference due to attachment of the manual worm drive to the horn mount assembly. Preferably, manipulation of the adjustment knob in a first manner produces manual polarization adjustment of the horn assembly in a clockwise direction while manipulation of the adjustment knob in a second manner produces manual polarization adjustment of the horn assembly in a counter-clockwise direction. Additionally, the flex drive torque cable has a length sufficient to facilitate manual polarization adjustment of the horn assembly from behind the antenna dish.
The present invention also resolves the above and other problems by providing a laser alignment device for positioning a horn mount assembly with respect to an antenna dish in an antenna system. The antenna dish has a centerpoint defined as the centerpoint of illumination. The horn mount assembly provides a mount for a horn assembly which transmits a signal along an axis towards the antenna dish, the axis being defined as a horn transmission beam axis. The laser alignment device includes an elongated body with attachment mounts for connecting to the horn mount assembly and a laser emitter contained within the body. The laser emitter projects a laser beam along the horn transmission beam axis. In this manner, the laser alignment device facilitates aligning the horn mount assembly to which the horn assembly will attach, with respect to the centerpoint of illumination of the antenna dish by using the laser projection along the horn transmission beam axis instead of requiring the antenna system to be actively transmitting.
In one preferred embodiment of the present invention, the laser alignment device is selectively attachable to the horn mount assembly, while in another preferred embodiment of the present invention the laser alignment device is permanently affixed to the horn mount assembly. The laser alignment device includes a power switch for the laser emitter. The horn mount assembly to which the laser alignment device attaches includes a feed strut attachment plate, a wave guide circular clamp, and a horn circular clamp. Preferably a first attachment mount of the laser alignment device is shaped and sized to correspondingly mate with the wave guide mount circular clamp of the horn mount assembly, and a second attachment mount of the laser alignment device is shaped and sized to correspondingly mate with the horn circular clamp of the horn mount assembly. In this manner, the laser alignment device is positioned and oriented to project a laser beam along the horn transmission beam axis by inserting the laser alignment device into the wave guide mount circular clamp and horn circular clamp of the horn mount assembly.
In another preferred aspect of the present invention, the antenna system further includes an alignment jig for positioning the horn with respect to the antenna dish. The alignment jig includes a central hub, a plurality of jig arms connecting at the central hub, and a reference ring suspending from the central hub. The plurality of jig arms are selectively securable to the antenna dish. The reference ring is positioned and oriented with respect to the antenna dish to provide a target for the horn to correspondingly mate against when the horn has been properly positioned and oriented. In this preferred aspect of the present invention, the laser alignment device further includes a mock horn disc that corresponds dimensionally to the horn assembly in both size and position when the laser sighting device is mounted on the horn mount assembly. The mock horn disc of the laser alignment device allows the alignment jig to be used simultaneously with the laser alignment device.
In one preferred embodiment of the present invention, the dish assembly, back frame assembly, rotary steering assembly, and collapsible mount assembly are deployable by a single person. Preferably, the steerable antenna assembly is collapsible, rapidly deployable, has very few parts, and is inexpensive compared to other types of known antenna systems.
Other features and advantages of the present invention will become apparent from the following detailed description, taken in conjunction with the accompanying drawings, which illustrate by way of example, the features of the present invention.